During this time, Finch continued to appear on stage in various productions while under contract to Olivier. Finch's closeness to the Olivier family led to an affair with Olivier's beautiful but increasingly unstable wife, Vivien Leigh, which began in 1948, and continued on and off for several years, ultimately falling apart due to her deteriorating mental condition.[23]

Finch returned to Australia to make The Shiralee (1957), one of his favourite parts, and the tenth most popular movie at the British box office that year. He followed it with another Australian story, the bushranger tale Robbery Under Arms (1957), which did less well. However exhibitors still voted Finch the third most popular British star of 1957, and the fifth most popular overall, regardless of nationality.[28]

“Peter and the team offer professionally run, competitive golf at the best courses in the UK. It has been a great way for me to play the top venues under tournament pressure whilst meeting people I now class as friends. A tight ship is run too, with no questionable handicaps and scores, which are well within reason, picking up prizes is a refreshing change. Since my involvement from 2014, you can see the tour growing naturally year on year and given the schedule who can see it stopping. Every event is top class – and glad to be apart of it.”

Finch's next three films saw him support notable female stars: Sophia Loren in Judith (1966), Melina Mercouri in 10:30 P.M. Summer (1966) and Julie Christie in Far from the Madding Crowd (1967). He was reunited with Aldrich for The Legend of Lylah Clare (1968). The Red Tent (1970) was an expensive international adventure film, with Finch as Umberto Nobile.

Finch co-wrote and directed an award-winning short film, The Day (1960) and announced plans to direct a feature but it did not eventuate. He won his third BAFTA for Best Actor for No Love for Johnnie (1961), although like Oscar Wilde, the film lost money. He was originally chosen to play Julius Caesar in Cleopatra (1963) and filmed scenes in London, but when the film was postponed he withdrew; the role was recast with Rex Harrison.

“Peter and the team offer professionally run, competitive golf at the best courses in the UK. It has been a great way for me to play the top venues under tournament pressure whilst meeting people I now class as friends. A tight ship is run too, with no questionable handicaps and scores, which are well within reason, picking up prizes is a refreshing change. Since my involvement from 2014, you can see the tour growing naturally year on year and given the schedule who can see it stopping. Every event is top class – and glad to be apart of it.”

Finch was nominated for an Oscar for Network and went on to posthumously win the award, which was accepted by his widow, Eletha Finch. Although James Dean, Spencer Tracy and Massimo Troisi were also posthumously nominated for a Best Actor Oscar, Finch was the first actor to have won the award posthumously, as well as the first Australian actor to win a Best Actor award. He was the only posthumous winner of an Oscar in an acting category until fellow Australian Heath Ledger won the Academy Award for Best Supporting Actor in 2009; there were many earlier posthumous Oscar winners in non-acting categories.[30][31] Finch also won five Best Actor awards from the British Academy of Film and Television Arts (BAFTA), including one for Network.

During this time, Finch continued to appear on stage in various productions while under contract to Olivier. Finch's closeness to the Olivier family led to an affair with Olivier's beautiful but increasingly unstable wife, Vivien Leigh, which began in 1948, and continued on and off for several years, ultimately falling apart due to her deteriorating mental condition.[23]